Base de dados : MEDLINE
Pesquisa : G16.500.285 [Categoria DeCS]
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[PMID]:28464290
[Au] Autor:Connell SD; Fernandes M; Burnell OW; Doubleday ZA; Griffin KJ; Irving AD; Leung JYS; Owen S; Russell BD; Falkenberg LJ
[Ad] Endereço:Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, North Terrace, The University of Adelaide, South Australia, Australia.
[Ti] Título:Testing for thresholds of ecosystem collapse in seagrass meadows.
[So] Source:Conserv Biol;31(5):1196-1201, 2017 10.
[Is] ISSN:1523-1739
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Although the public desire for healthy environments is clear-cut, the science and management of ecosystem health has not been as simple. Ecological systems can be dynamic and can shift abruptly from one ecosystem state to another. Such unpredictable shifts result when ecological thresholds are crossed; that is, small cumulative increases in an environmental stressor drive a much greater change than could be predicted from linear effects, suggesting an unforeseen tipping point is crossed. In coastal waters, broad-scale seagrass loss often occurs as a sudden event associated with human-driven nutrient enrichment (eutrophication). We tested whether the response of seagrass ecosystems to coastal nutrient enrichment is subject to a threshold effect. We exposed seagrass plots to different levels of nutrient enrichment (dissolved inorganic nitrogen) for 10 months and measured net production. Seagrass response exhibited a threshold pattern when nutrient enrichment exceeded moderate levels: there was an abrupt and large shift from positive to negative net leaf production (from approximately 0.04 leaf production to 0.02 leaf loss per day). Epiphyte load also increased as nutrient enrichment increased, which may have driven the shift in leaf production. Inadvertently crossing such thresholds, as can occur through ineffective management of land-derived inputs such as wastewater and stormwater runoff along urbanized coasts, may account for the widely observed sudden loss of seagrass meadows. Identification of tipping points may improve not only adaptive-management monitoring that seeks to avoid threshold effects, but also restoration approaches in systems that have crossed them.
[Mh] Termos MeSH primário: Ecossistema
Eutrofização
[Mh] Termos MeSH secundário: Conservação dos Recursos Naturais
Oceanos e Mares
Poaceae
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180310
[Lr] Data última revisão:
180310
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170503
[St] Status:MEDLINE
[do] DOI:10.1111/cobi.12951


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[PMID]:29478654
[Au] Autor:Lü C; He J; Wang B
[Ad] Endereço:School of Ecology and Environment, Inner Mongolia University, Huhhot 010021, China; Institute of Environmental Geology, Inner Mongolia University, Huhhot 010021, China. Electronic address: lcw2008@imu.edu.cn.
[Ti] Título:Spatial and historical distribution of organic phosphorus driven by environment conditions in lake sediments.
[So] Source:J Environ Sci (China);64:32-41, 2018 Feb.
[Is] ISSN:1001-0742
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The chemistry of sedimentary organic phosphorus (OP) and its fraction distribution in sediments are greatly influenced by environmental conditions such as terrestrial inputs and runoffs. The linkage of OP with environmental conditions was analyzed on the basis of OP spatial and historical distributions in lake sediments. The redundancy analysis and OP spatial distribution results suggested that both NaOH-OP (OP extracted by NaOH) and Re-OP (residual OP) in surface sediments from the selected 13 lakes reflected the gradient effects of environmental conditions and the autochthonous and/or allochthonous inputs driven by latitude zonality in China. The lake level and salinity of Lake Hulun and the runoff and precipitation of its drainage basin were reconstructed on the basis of the geochemistry index. This work showed that a gradient in weather conditions presented by the latitude zonality in China impacts the OP accumulation through multiple drivers and in many ways. The drivers are mainly precipitation and temperature, governing organic matter (OM) production, degradation rate and transportation in the watershed. Over a long temporal dimension (4000years), the vertical distributions of Re-OP and NaOH-OP based on a dated sediment profile from HLH were largely regulated by the autochthonous and/or allochthonous inputs, which depended on the environmental and climate conditions and anthropogenic activities in the drainage basin. This work provides useful environmental geochemistry information to understand the inherent linkage of OP fractionation with environmental conditions and lake evolution.
[Mh] Termos MeSH primário: Monitoramento Ambiental
Fósforo/análise
Poluentes Químicos da Água/análise
Poluição Química da Água/estatística & dados numéricos
[Mh] Termos MeSH secundário: Fracionamento Químico
China
Eutrofização
Sedimentos Geológicos/química
Lagos/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Water Pollutants, Chemical); 27YLU75U4W (Phosphorus)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180301
[Lr] Data última revisão:
180301
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180227
[St] Status:MEDLINE


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[PMID]:29324791
[Au] Autor:Arnold TE; Kenney WF; Curtis JH; Bianchi TS; Brenner M
[Ad] Endereço:Department of Geological Sciences, University of Florida, Gainesville, Florida, United States of America.
[Ti] Título:Sediment biomarkers elucidate the Holocene ontogeny of a shallow lake.
[So] Source:PLoS One;13(1):e0191073, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We carried out geochemical analyses on a sediment core from Lake Harris, Florida (USA) to identify sources of organic matter to the sediment throughout the Holocene, and relate changes in those sources to shifts in past climate and environmental conditions. We hypothesized that the sources of organic matter changed in response to regional hydrologic shifts following de-glaciation, and to human population expansion in the state during the 20th century. Hydroclimate shifts in Florida were related to: 1) a steady rise in relative sea level and the fresh water table that began in the early Holocene, 2) wetland formation and expansion ca. 5,000 cal yrs BP, and 3) the onset of the modern El Niño (ENSO) cycle ~3,000 cal yrs BP. Stratigraphic changes in sediment variables from Lake Harris reflect each of these hydroclimate periods. Early in the Holocene, Lake Harris was a marsh-like system in a relatively dry, open-prairie environment. Organic sediments deposited at that time were derived largely from terrestrial sources, as inferred from high TOC/TN ratios, a dominance of longer-chain of n-alkanes (n-C29-31), relatively negative organic carbon isotope values (δ13CTOC), and low biogenic silica concentrations. In the middle Holocene, a positive shift in δ13CTOC coincided with the onset of wetter conditions in Florida. Submerged macrophyte biomarkers (n-C21-23) dominated, and during that period bulk organic carbon isotope values were most similar to δ13C values of mid-chain-length n-alkanes. In the late Holocene, δ13CTOC values declined, CaCO3 levels decreased to trace amounts, organic carbon concentrations increased and diatom biogenic silica concentrations increased from 10 to 120 mg g-1. Around 2,900 cal yrs BP, the effects of ENSO intensified and many Florida lakes deepened to their current limnetic state. Concentrations of algal and cyanobacterial biomarkers in the Lake Harris core increased by orders of magnitude after about AD 1940, in response to human-induced eutrophication, an inference supported by values of δ15N that fluctuate around zero.
[Mh] Termos MeSH primário: Biomarcadores/metabolismo
Sedimentos Geológicos/química
Lagos
[Mh] Termos MeSH secundário: Mudança Climática
Eutrofização
Florida
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Biomarkers)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180223
[Lr] Data última revisão:
180223
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180112
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0191073


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[PMID]:29335403
[Au] Autor:Mignot A; Ferrari R; Claustre H
[Ad] Endereço:Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. mignot@obs-vlfr.fr.
[Ti] Título:Floats with bio-optical sensors reveal what processes trigger the North Atlantic bloom.
[So] Source:Nat Commun;9(1):190, 2018 01 15.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The North Atlantic bloom corresponds to a strong seasonal increase in phytoplankton that produces organic carbon through photosynthesis. It is still debated what physical and biological conditions trigger the bloom, because comprehensive time series of the vertical distribution of phytoplankton biomass are lacking. Vertical profiles from nine floats that sampled the waters of the North Atlantic every few days for a couple of years reveal that phytoplankton populations start growing in early winter at very weak rates. A proper bloom with rapidly accelerating population growth rates instead starts only in spring when atmospheric cooling subsides and the mixed layer rapidly shoals. While the weak accumulation of phytoplankton in winter is crucial to maintaining a viable population, the spring bloom dominates the overall seasonal production of organic carbon.
[Mh] Termos MeSH primário: Técnicas Biossensoriais/instrumentação
Monitoramento Ambiental/métodos
Eutrofização/fisiologia
Fotossíntese/fisiologia
Fitoplâncton/fisiologia
[Mh] Termos MeSH secundário: Oceano Atlântico
Biomassa
Clorofila/fisiologia
Monitoramento Ambiental/instrumentação
Estações do Ano
Água do Mar
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
1406-65-1 (Chlorophyll)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180222
[Lr] Data última revisão:
180222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180117
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02143-6


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[PMID]:29315312
[Au] Autor:Cyronak T; Andersson AJ; Langdon C; Albright R; Bates NR; Caldeira K; Carlton R; Corredor JE; Dunbar RB; Enochs I; Erez J; Eyre BD; Gattuso JP; Gledhill D; Kayanne H; Kline DI; Koweek DA; Lantz C; Lazar B; Manzello D; McMahon A; Meléndez M; Page HN; Santos IR; Schulz KG; Shaw E; Silverman J; Suzuki A; Teneva L; Watanabe A; Yamamoto S
[Ad] Endereço:Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States of America.
[Ti] Título:Taking the metabolic pulse of the world's coral reefs.
[So] Source:PLoS One;13(1):e0190872, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Worldwide, coral reef ecosystems are experiencing increasing pressure from a variety of anthropogenic perturbations including ocean warming and acidification, increased sedimentation, eutrophication, and overfishing, which could shift reefs to a condition of net calcium carbonate (CaCO3) dissolution and erosion. Herein, we determine the net calcification potential and the relative balance of net organic carbon metabolism (net community production; NCP) and net inorganic carbon metabolism (net community calcification; NCC) within 23 coral reef locations across the globe. In light of these results, we consider the suitability of using these two metrics developed from total alkalinity (TA) and dissolved inorganic carbon (DIC) measurements collected on different spatiotemporal scales to monitor coral reef biogeochemistry under anthropogenic change. All reefs in this study were net calcifying for the majority of observations as inferred from alkalinity depletion relative to offshore, although occasional observations of net dissolution occurred at most locations. However, reefs with lower net calcification potential (i.e., lower TA depletion) could shift towards net dissolution sooner than reefs with a higher potential. The percent influence of organic carbon fluxes on total changes in dissolved inorganic carbon (DIC) (i.e., NCP compared to the sum of NCP and NCC) ranged from 32% to 88% and reflected inherent biogeochemical differences between reefs. Reefs with the largest relative percentage of NCP experienced the largest variability in seawater pH for a given change in DIC, which is directly related to the reefs ability to elevate or suppress local pH relative to the open ocean. This work highlights the value of measuring coral reef carbonate chemistry when evaluating their susceptibility to ongoing global environmental change and offers a baseline from which to guide future conservation efforts aimed at preserving these valuable ecosystems.
[Mh] Termos MeSH primário: Recifes de Corais
[Mh] Termos MeSH secundário: Ácidos/análise
Carbono/análise
Ecossistema
Eutrofização
Aquecimento Global
Concentração de Íons de Hidrogênio
Água do Mar/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Acids); 7440-44-0 (Carbon)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180222
[Lr] Data última revisão:
180222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180110
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0190872


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[PMID]:29239717
[Au] Autor:Cai H; Cui H; Zeng Y; Wang Y; Jiang H
[Ad] Endereço:1​State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, PR China.
[Ti] Título:Niveispirillum lacus sp. nov., isolated from cyanobacterial aggregates in a eutrophic lake.
[So] Source:Int J Syst Evol Microbiol;68(2):507-512, 2018 Feb.
[Is] ISSN:1466-5034
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:A bacterial strain, 1-14 , was isolated from cyanobacterial aggregates in a eutrophic lake, Taihu Lake, China. Cells were observed to be slightly curved, rod-shaped, aerobic and Gram-stain-negative. Optimal growth occurred at pH 7.0 (range: 5.0-9.0), 28 °C (range: 20-32 °C) and 0 % (w/v) NaCl (range: 0-1.0 %) in R2A broth. No growth is observed at 37 °C. The cells were found to be positive for oxidase and catalase activities. The major respiratory quinone was ubiquinone Q-10. The major fatty acids (>10 %) were identified as C18 : 1ω6c/C18 : 1ω7c, C16 : 0 3-OH and C18 : 1 2-OH. The major polar lipids were found to consist of phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol and phosphatidylcholine. Within the genus Niveispirillum, strain 1-14 was most closely related to Niveispirillum cyanobacteriorum TH16 (98.3 % 16S rRNA gene sequence similarity), followed by Niveispirillum irakense DSM 11586 (97.8 %) and Niveispirillum fermenti CC-LY736 (97.0 %). The genomic G+C content of strain 1-14 was 62.2 mol% based on total genome calculations. Genes coding for light-harvesting complexes LHI and LHII, and a photosynthetic reaction centre were detected in the genome. Average nucleotide identities and digital DNA-DNA hybridizations for complete genomes ranged from 76.4 to 83.5 and from 21.5 to 27.4 % between strain 1-14 and strains within the genus Niveispirillum. The phenotypic, chemotaxonomic and phylogenetic properties, and genome analysis suggested that strain 1-14 represents a novel species within the genus Niveispirillum, for which the name Niveispirillum lacus sp. nov. is proposed. The type strain is 1-14 (=CGMCC 1.12980 =LMG 28363 ).
[Mh] Termos MeSH primário: Eutrofização
Lagos/microbiologia
Filogenia
Rhodospirillaceae/classificação
[Mh] Termos MeSH secundário: Técnicas de Tipagem Bacteriana
Composição de Bases
China
Cianobactérias/classificação
Cianobactérias/genética
Cianobactérias/isolamento & purificação
DNA Bacteriano/genética
Ácidos Graxos/química
Hibridização de Ácido Nucleico
Fosfolipídeos/química
RNA Ribossômico 16S/genética
Rhodospirillaceae/genética
Rhodospirillaceae/isolamento & purificação
Análise de Sequência de DNA
Ubiquinona/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Bacterial); 0 (Fatty Acids); 0 (Phospholipids); 0 (RNA, Ribosomal, 16S); 1339-63-5 (Ubiquinone); I7T5V2W47R (Ubiquinone Q2)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180212
[Lr] Data última revisão:
180212
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171215
[St] Status:MEDLINE
[do] DOI:10.1099/ijsem.0.002526


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[PMID]:29364599
[Au] Autor:Mukhanovi VS; Rylkova OA; Churiloval TY; Sakhon EG; Pimenov NV
[Ti] Título:Structure and Seasonal Trophodynamics of Picophytoplankton in Sevastopol Bay and Adjacent Waters (the Black Sea).
[So] Source:Mikrobiologiia;85(5):512-521, 2016 Sep.
[Is] ISSN:0026-3656
[Cp] País de publicação:Russia (Federation)
[La] Idioma:eng
[Ab] Resumo:Abundance and seasonal trophodynamics. (specific growth rate, daily production, and grazing mortality) of the major picophytoplankton components, Synechococcus cyanobacteria (Syn) and picoeukary- otes (Pico-E), were studied at three stations in Sevastopol Bay and adjacent coastal waters (the Black Sea) in 2014 by flow cytometry and the dilution method. Pico- E abundance was shown to increase along the nutrient and pollution gradient from the coastal waters outside the bay (annual average of 7.3 ± 5.4 x 103 cells mL⁻¹) to the eastern corner of the bay (28.7 ± 11.4 x 103 cells mL⁻¹), while no relation was found between the water pollution status.and Syn abundance (9.9 ± 8.7 x 10³ cells mL⁻¹, at all the stations, n=27). Matter flows through the communities (daily production for Syn and Pico-E 0-16.6 and 0-19.3 µg C L- day⁻¹, respec- tively; grazing mortality for Syn and PicoE 0-3.6 and 0-21.2 µg C L⁻¹ day⁻¹, respectively) were comparable to or even exceeded their biomass stocks (<0.05-6.8 and 0.9-26.5 µg C L- for Syn and PicoE, respectively), indicating high biomass turnover rates. The highest flow-to-stock ratio (up to 6 for Syn) and,a significant imbalance between daily production (P) and grazing mortality (G) were observed in the most polluted and eu- trophicated waters of the bay in spring (Pico-E: P/G <.1) and late summer (Syn: P/G > 1). Black River inflow to the bay was hypothesized to be among the mechanisms maintaining.this pronounced and long-term im- balance in the open system without any negative consequences for the picophytoplankton assemlages.
[Mh] Termos MeSH primário: Eutrofização/fisiologia
Fitoplâncton/crescimento & desenvolvimento
Synechococcus/crescimento & desenvolvimento
[Mh] Termos MeSH secundário: Carga Bacteriana
Baías
Biomassa
Mar Negro
Contagem de Células
Ecossistema
Fitoplâncton/classificação
Fitoplâncton/metabolismo
Estações do Ano
Synechococcus/metabolismo
Poluição da Água/análise
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180208
[Lr] Data última revisão:
180208
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180125
[St] Status:MEDLINE


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[PMID]:28747475
[Au] Autor:Rogalski MA; Leavitt PR; Skelly DK
[Ad] Endereço:School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA rogalski@umich.edu.
[Ti] Título:Daphniid zooplankton assemblage shifts in response to eutrophication and metal contamination during the Anthropocene.
[So] Source:Proc Biol Sci;284(1859), 2017 Jul 26.
[Is] ISSN:1471-2954
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Human activities during the Anthropocene result in habitat degradation that has been associated with biodiversity loss and taxonomic homogenization of ecological communities. Here we estimated effects of eutrophication and heavy metal contamination, separately and in combination, in explaining zooplankton species composition during the past 125-145 years using analysis of daphniid diapausing egg banks from four lakes in the northeastern USA. We then examined how these community shifts influenced patterns of diversity and homogenization. Analysis of past lake production (via subfossil pigments) and metal contamination (via sedimentary metals) demonstrated that eutrophication alone (19-39%) and in combination with metal pollution (17-54%) explained 36-79% of historical variation in daphniid species relative abundances in heavily fertilized lakes. In contrast, metal pollution alone explained the majority (72%) of historical variation in daphniid assemblages at the oligotrophic site. Several species colonization events in eutrophying lakes resulted in increased species richness and gamma diversity through time. At the same time, daphniid assemblages in three eutrophied lakes became more similar to each other (homogenized), but this pattern was only seen when accounting for species presence/absence. We did not observe consistent patterns of divergence between the assemblages in the eutrophying lakes and the low-nutrient reference site. Given the pervasive nature of fertilization and metal pollution, and the sensitivity of cladocerans to these factors, we suggest that many inhabited lake districts may already exhibit similar patterns of daphniid assemblage shifts.
[Mh] Termos MeSH primário: Eutrofização
Metais Pesados/análise
Poluentes Químicos da Água/análise
Zooplâncton/classificação
[Mh] Termos MeSH secundário: Animais
Biodiversidade
Lagos/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Metals, Heavy); 0 (Water Pollutants, Chemical)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180202
[Lr] Data última revisão:
180202
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170728
[St] Status:MEDLINE


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[PMID]:29021095
[Au] Autor:Jalil A; Li Y; Du W; Wang W; Wang J; Gao X; Khan HOS; Pan B; Acharya K
[Ad] Endereço:Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, China; College of Environment, Hohai University, Nanjing, 210098, China.
[Ti] Título:The role of wind field induced flow velocities in destratification and hypoxia reduction at Meiling Bay of large shallow Lake Taihu, China.
[So] Source:Environ Pollut;232:591-602, 2018 Jan.
[Is] ISSN:1873-6424
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Wind induced flow velocity patterns and associated thermal destratification can drive to hypoxia reduction in large shallow lakes. The effects of wind induced hydrodynamic changes on destratification and hypoxia reduction were investigated at the Meiling bay (N 31° 22' 56.4″, E 120° 9' 38.3″) of Lake Taihu, China. Vertical flow velocity profile analysis showed surface flow velocities consistency with the wind field and lower flow velocity profiles were also consistent (but with delay response time) when the wind speed was higher than 6.2 m/s. Wind field and temperature found the control parameters for hypoxia reduction and for water quality conditions at the surface and bottom profiles of lake. The critical temperature for hypoxia reduction at the surface and the bottom profile was ≤24.1C° (below which hypoxic conditions were found reduced). Strong prevailing wind field (onshore wind directions ESE, SE, SSE and E, wind speed ranges of 2.4-9.1 m/s) reduced the temperature (22C° to 24.1C°) caused reduction of hypoxia at the near surface with a rise in water levels whereas, low to medium prevailing wind field did not supported destratification which increased temperature resulting in increased hypoxia. Non-prevailing wind directions (offshore) were not found supportive for the reduction of hypoxia in study area due to less variable wind field. Daytime wind field found more variable (as compared to night time) which increased the thermal destratification during daytime and found supportive for destratification and hypoxia reduction. The second order exponential correlation found between surface temperature and Chlorophyll-a (R : 0.2858, Adjusted R-square: 0.2144 RMSE: 4.395), Dissolved Oxygen (R : 0.596, Adjusted R-square: 0.5942, RMSE: 0.3042) concentrations. The findings of the present study reveal the driving mechanism of wind induced thermal destratification and hypoxic conditions, which may further help to evaluate the wind role in eutrophication process and algal blooms formation in shallow water environments. OUTCOME: Wind field is the key control factor for thermal destratification and hypoxia reduction. 24.1C° is the critical/threshold temperature for hypoxia, Chlorophyll-a and NH -N concentrations of the shallow freshwater lake.
[Mh] Termos MeSH primário: Monitoramento Ambiental
Eutrofização
Lagos/química
Vento
[Mh] Termos MeSH secundário: Baías/química
China
Clorofila/análise
Hidrodinâmica
Temperatura Ambiente
Qualidade da Água
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
1406-65-1 (Chlorophyll); YF5Q9EJC8Y (chlorophyll a)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180119
[Lr] Data última revisão:
180119
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171013
[St] Status:MEDLINE


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[PMID]:29182651
[Au] Autor:Natsuike M; Saito R; Fujiwara A; Matsuno K; Yamaguchi A; Shiga N; Hirawake T; Kikuchi T; Nishino S; Imai I
[Ad] Endereço:Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido, Japan.
[Ti] Título:Evidence of increased toxic Alexandrium tamarense dinoflagellate blooms in the eastern Bering Sea in the summers of 2004 and 2005.
[So] Source:PLoS One;12(11):e0188565, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The eastern Bering Sea has a vast continental shelf, which contains various endangered marine mammals and large fishery resources. Recently, high numbers of toxic A. tamarense resting cysts were found in the bottom sediment surface of the eastern Bering Sea shelf, suggesting that the blooms have recently occurred. However, little is known about the presence of A. tamarense vegetative cells in the eastern Bering Sea. This study's goals were to detect the occurrence of A. tamarense vegetative cells on the eastern Bering Sea shelf and to find a relationship between environmental factors and their presence. Inter-annual field surveys were conducted to detect A. tamarense cells and environmental factors, such as nutrients, salinity, chlorophyll a, and water temperature, along a transect line on the eastern Bering Sea shelf during the summers of 2004, 2005, 2006, 2009, 2012, and 2013. A. tamarense vegetative cells were detected during every sampling year, and their quantities varied greatly from year to year. The maximum cell densities of A. tamarense observed during the summers of 2004 and 2005 were much higher than the Paralytic shellfish poisoning warning levels, which are greater than 100-1,000 cells L-1, in other subarctic areas. Lower quantities of the species occurred during the summers of 2009, 2012, and 2013. A significant positive correlation between A. tamarense quantity and water temperature and significant negative correlations between A. tamarense quantity and nutrient concentrations (of phosphate, silicate, and nitrite and nitrate) were detected in every sampling period. The surface- and bottom-water temperatures varied significantly from year to year, suggesting that water temperatures, which have been known to affect the cell growth and cyst germination of A. tamarense, might have affected the cells' quantities in the eastern Bering Sea each summer. Thus, an increase in the Bering Sea shelf's water temperature during the summer will increase the frequency and scale of toxic blooms and the toxin contamination of plankton feeders. This poses serious threats to humans and the marine ecosystem.
[Mh] Termos MeSH primário: Dinoflagelados/metabolismo
Eutrofização
Água do Mar/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171226
[Lr] Data última revisão:
171226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171129
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0188565



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